Ignition distributor



June 29, 1948. J. l.. ARTHUR IGNITION DISTRIBUTOR Filed Feb. 9, 1945 w ,Awb

ATTORNEY# Patented June 29, 1948 IGNITION DISTRIBUTOR James L. Arthur, Indianapolis, Ind., alslgnorjto General Motors Corporation, Detroit, Mich., a corporation of Delaware Application-February 9, 1945, Serial No. 577,093

3 Claims.

This invention relates to ignition distributors particularly for airplane use.

Its object is to improve the operation of an ignition distributor which is required to operate at any altitude. This-.object is accomplished by completely filling the distributor housing with oil which has good dielectric properties and by providing for such movement of the oil within the distributor housing as will avoid alignment or the chaining, due to electrical stress, of moisture globules which, if not disturbed, would provide a vconducting path for current at high voltage. The agitation of the oil is insuiiicient to cause foaming which would impair the dielectric properties of the oil.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown.

In the drawings Figs. 1 and 2 are longitudinal sectional views of ignition distributors embodying diierent forms of the invention. Fig. 3 is a view of the rotor I1' of Fig. 2 looking in the direction of arrow 3 of Fig. 2 and is drawn to a smaller scale than Fig. 2.

In Fig. 1 there is shown anV ignition distributor I adapted to be mounted Within the tubular portion I of a part of the engine block, for example, the part which encloses the valve-operating cam shaft. The housing I0 supports a bearing frame I2 integral with a plate I3 through which screws I4 pass for securing the bearing frame to the housing. The bearing frame supports a bearing bushing I5 in which a distributor shaft I8 is journaled. Shaft I6 drives a distributor rotor I'I' carrying a distributing blade Il, the outer end I9 of which is caused to pass between and to engage a plurality of pairs of contacts, each pair comprising contacts and 2| secured to an annular ledge 22 integral with a non-conducting cylinder 23 attached by screws 24 to the plate I3.

The distributor housing I0 is. closed by distributor cap of insulating material molded around a center insert 3| and a plurality of inserts 32 arranged in a circular row coaxial with the shaft I6. These inserts are connectable with insulated wires which are held in place by the ,tightening of bushings 33 which compress resilient non-conducting washers 34 around the insulation of the wires. The inner contact 3| is in engagement with a button Ia provided by the rotor blade I8. Each'of the contacts 32 is electrlcally connected with contacts 2|'.and through the metal rivets 2Ia with the contacts 20.

(Cl. 20o-19) Where the engine lubricating oil has satisfactory dielectric properties the engine pressure oil line is connected with a duct 40 from which oil under pressure ows through a seal washer 4|, a check valve 42 and a passage 43 in the housing IU, through a hole 44 in the frame I2, through an annular groove 45 in the bushing II and through a longitudinal groove 46 therein to the interior of the distributor housingty Some oil flows from groove 45 through hole 45a to lubricate the shaft I6 and the interior of bushing I5. The housing is completely lled; and the excess escapes through a passage 41. If it is necessary to fill the housing with oil beforedt is filled by the circulation of the engine oil, such oil is introduced through an opening 48 closed by a filler plug 4S. .y

The plate I3, the non-conducting cylinder 2l and the non-conducting cap 30 provide a chamber in which oil enters near'the center thereof from the groove 4i. Oil ilows generally radially from the central portion of this chamber toward the cylinder 23 and passes out through holes lia in plate I3, there being a number of these holes equally-spaced in a circular row. As the oil thus circulates radially, its movement is intercepted by a vane Ila of the rotor I1 and, tous lesser extent, by the blade I8. The agitation of the oil as it moves generally radially prevents the chaining of moisture globules which, if allowed to chain. would provide a path of relatively low resistance for the high tension current'. and might divert the sparking impulse from i the proper spark-plug directly to ground through some metallic part of the distributor housing or in directly to ground through some other spark-plug in a cylinder then under relatively low pressure. The agitation is of a mild nature .sudicient to prevent chaining of moisture globules but insuiilcient to cause foaming of the oil. All of the oil in proximity to the end portion I9 of the blade I8 and the rows of conta-cts 20 and 2| is kept in motion in currents which constantly change in direction so that alignment of moisture globules under electrical stress will not occur.

As the blade passes between a pair of contacts 20, 2|, the oil therebetween serving as a lubricant is a thin nlm through which the high tension current will pass.

In the form shown in Fig. 2 the oil from the engine is conducted from the passage 4I of the housing I0 through a hole 44' in the bearing frame I2' through a hole 45' in the bushing I" and through a hole III in the shaft I6' which is hollow and is closed at the driving end by plug 6|.- From the shaft the oil passes through a channel 62 provided in the distributor rotor I1 which is driven by the shaft I6'. The channel 62 leads to a groove 63 in the bar-like portion 68 of the rotor I'l (Fig. 3). The groove 63 receives a rotor blade 64 secured to the rotor Il' by a pin 65. 'I'he inner end of blade 84 engages the center contact 3i and the outer end of blade BI wipes across the contacts 32. The bar-like portion 66 fits closely within the cap 30.

The walls of the groove 63 together with the.

inner walls of the capl30 provide a chamber through which oil tends to circulate from near the axis of rotation of the rotor i1 generally in a radial direction. However, as the body of oil within the groove tends to move radially, such movement is being continually intercepted by cross currents which exist by reason of the fact that the body of oil is being rotated about the axis of the rotor I1. Oil will pass from the groove 63 through the narrow space between the cap 30 and the long side edges 61 of the bar 66. All of the oil in `proximity to the blade 64 receives agitation suliiicientto prevent the chaining of moisture globules in a region which is subjected to electrical stress. Agitation is insuillcient to cause foaming of the oil.

In both forms of distributors, the prevention of chaining of moisture globules is accomplished by fundamentally the same method. That method is to intercept by a mild agitation the generally radial flow of the oil in proximity to the distributor rotor. The distributor shown in Fig. 1 is one which provides for inspection of the distributor blade and distributing contacts in assembled relation when the cover 30 is removed. On account of this feature, the body of oil to be agitated is greater than in the case of the distributor shown in Fig, 2 when only a small body of oil is subjected to agitation at any instant. Therefore the rotor i1 of the distributor shown in Fig. 1 should have an agitating vane Ila.

While the embodiments of the present invention as herein disclosed, constitute preferred forms, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. An ignition distributor having a highvoltage terminal and spark-plug cable terminals, distributing contacts respectivelyT connected with the spark-plug cable terminals and arranged in a circular row, a shaft, a conducting blade insulatingly supported by the shaft for distributing high tension current from the high voltage terminal to the contacts, a housing for contacts and blade having an inlet near the shaft axis for admission of oil under pressure and an outlet at the uppermost part thereof for overflow of oil when the housing is full, a chamber within the housing receiving the oil entering the housing near the shaft axis and through which oil tends to flow generally in a radial direction outwardly from a region near the shaft axis, and means rotated by the shaft for causing a mild agitation of the oil flowing in the chamber in order to prevent chaining of moisture globules.

2. A distributor according to claim 1 in which the chamber is provided by a non-conducting cylinder which supports the distributing contacts, by a plate supported within the housing and having outlets near the interior wall of the cylinder and by a non-conducting cap supporting the distributor terminals, and in which the oilagitating means is -provided by a vane rotated by the shaft.

3. A distributor according to claim 1 in which the chamber is provided by the inner wall of a non-conducting cap supporting the distributor terminals and by a diametrically located, transversely extending groove provided by a bar-like rotor driven by the shaft, the distributing blade being located within the groove and attached to the rotor, the oil inlet conduit including a passage through the shaft and leading to the rotor, and a passage through the rotor leading to the groove near the axis of the shaft, and in which the oil agitatng means includes the groove side edge surfaces which are closely spaced from the interior of the distributor cap.

JAMES L. ARTHUR.

REFERENCES CITED Tho following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 858,730 LePontois July 2, 1907 860,383 Hutchinson July 19, 1907 1,062,738 Schmidt May 27, 1913 1,658,508 Anderson Feb. 7, 1928 

